干旱区石灰岩矿山遗迹地生态修复模式对比研究

A comparative study of ecological remediation approaches in arid limestone mining remnants

矿山遗迹地的生态修复是促进人与自然和谐共生、实现绿色低碳发展的重要举措。干旱区矿山遗迹地立地条件差,植被覆盖率低,采矿活动造成的土壤侵蚀强烈,确定科学合理的恢复模式是生态修复成功与否的关键。以宁夏中卫市的典型石灰岩矿山遗迹地为研究对象,通过对比7种生态修复植物在不同土壤基质重构措施下的土壤温、湿度和有机质,以及植物的存活率和新生枝相对生长速率(Relative growth rate of new shoots,RGRs)等指标,筛选出适宜干旱区石灰岩矿山遗迹地生态修复的最优模式,构建了土壤改良-植被重建联合的生态恢复方案。结果表明:(1)土壤基质重构措施是石灰岩矿山生态修复的前提条件,有效地改善了植物定植环境,不同土壤基质重构模式的植物存活率表现为:土+有机肥>砂+土+有机肥>砂+土+复合肥;(2)土壤有机质的范围为0.56~2.84 g·kg^(-1),植物种和土壤基质及二者的交互作用对土壤有机质含量具有极显著影响(P<0.001);(3)RGRs的范围为1.51~1.87 mm·cm^(-1)·month^(-1),不同植物种的RGRs存在显著性差异;(4)通过系统聚类分析得到本研究区最适宜的生态修复模式为砂+土+有机肥(沙拐枣或短穗柽柳)。本研究从土壤改良-植被重建角度提出的联合生态修复方案可为干旱区矿山生态修复提供理论依据和实践参考。

The ecological restoration of mine sites is an important measure to promote the harmonious coexistence between humans and nature,and achieve green and low-carbon development.Mining remnants in arid area are characterized by poor site conditions,low vegetation coverage,and strong soil erosion caused by mining activities.The determination of a scientifically rational restoration model is crucial for the success of ecological restoration.In this study,the typical arid limestone mining remnants in Zhongwei City,Ningxia,were selected as the research object.By comparing the soil temperature,humidity,organic matter,plant survival rate,and relative growth rate of new shoots(RGRs)of seven kinds of ecological restoration plants under different soil matrix reconstruction measures,it aims to screen out the optimal mode for ecological restoration of arid limestone mining wastelands and construct an eco-restoration plan combining soil improvement and vegetation reconstruction.The results show that:(1)Soil matrix reconstruction measures are the prerequisite for ecological restoration of limestone mines,which can effectively improve plant colonization environment.The plant survival rates of different soil matrix reconstruction measures are:soil+organic fertilizer>sand+soil+organic fertilizer>sand+soil+compound fertilizer.(2)The range of soil organic matter was 0.56-2.84 g·kg^(-1).Plant species and soil matrix and their interaction had a significant effect on soil organic matter content(P<0.001).(3)The range of RGRs was 1.51^(-1).87 mm·cm^(-1)·month^(-1),and there were significant differences in RGRs among different plant species.(4)Through Hierarchical clustering analysis,the most suitable ecological restoration mode for the study area was found to be sand+soil+organic fertilizer(with Calligonum mongolicum or Tamarix ramosissima as the selected plants).This study proposes a joint ecological restoration scheme from the perspective of soil improvement-vegetation reconstruction,which can provide theoretical basis and practical reference for mine ecological restoration in arid areas.